Slide fasteners are widely applied to various clothing. A resin slide fastener has an advantage of reduced weight as compared to a metal slide fastener, and thus is widely applied in cases where weight reduction is required.
FIG. 1 is a schematic view showing an entire conventional slide fastener, and shows a conventional slide fastener 100 including a tape 10, elements 20, and a slider 30. The tape 10 and the elements 20 are installed together to form a fastener stringer. FIGS. 2(a) to 2(d) show the elements 20 in the conventional slide fastener viewed from four different angles, in which FIG. 2(a) is a perspective view, FIG. 2(b) is a front view, FIG. 2(c) is a top view, and FIG. 2(d) is a right side view. Each of the elements 20 include a main body 201, an installing portion 202, a neck 203, and a head 204. The main body 201 includes an upper main body 2011 and a lower main body 2012, and the upper main body 2011 and the lower main body 2012 are substantially rectangular when viewed from one side. The installing portion 202 is used for installing the tape 10 of the slide fastener 100, and the neck 203 is used for connecting the main body 201 and the head 204.
Currently, there is occasionally a need of further weight reduction of a resin slide fastener, which requires improvement of conventional elements by using lighter materials or optimizing and improving the structure of the elements. When improving the structure of the elements, it is necessary to guarantee both installation strength of the elements and smoothness and reliability in use of the slide fastener. Accordingly, there remains various demands on conventional slide fasteners, such as further weight reduction and guarantee of strength and smoothness in use.